Auditory Evoked Potentials from the Frog Eighth Nerve.

摘要

The auditory system of the frog has previously been studied with evoked potentials (among other techniques) at several levels of the nervous system. Although electrodes were placed into neural tissue in most of the studies, in one case wires placed through holes in the skull midline were used. The midline evoked potentials had multiple peaks which were attributed to unspecified centers of neural activity. In the present study, evoked potentials were recorded using a midline electrode and an electrode placed lateral to the inner ear to enhance the recording of the eighth-nerve component. Bullfrogs (Rana catesbeiana) of either sex were used in experiments. A prominent bipolar wave recorded at 3-6 ms is attributable to eighth-nerve activity. The evoked potential provides an integrated response for study of inner ear activity. Since the frog can sense extratympanic body and substrate vibrations, the eighth-nerve evoked potential described here is most likely a composite auditory and seismic sensory response. (edc)